Simulink Control Design™ - MathWorks

Variance Goal

Purpose

Limit white-noise impact on specified output signals, when using Control System Tuner.

Description

Variance Goal imposes a noise attenuation constraint that limits the impact on specified

output signals of white noise applied at specified inputs. The noise attenuation is

measured by the ratio of the noise variance to the output variance.

For stochastic inputs with a nonuniform spectrum (colored noise), use “Weighted Variance

Goal” on page 10-123 instead.

Creation

In the Tuning tab of Control System Tuner, select New Goal > Signal variance

attenuation to create a Variance Goal.

Command-Line Equivalent

When tuning control systems at the command line, use TuningGoal.Variance to

specify a constraint on noise amplification.

I/O Transfer Selection

Use this section of the dialog box to specify noise input locations and response outputs.

Also specify any locations at which to open loops for evaluating the tuning goal.

• Specify stochastic inputs

Select one or more signal locations in your model as noise inputs. To constrain a SISO

response, select a single-valued input signal. For example, to constrain the gain from a

location named 'u' to a location named 'y', click Add signal to list and select

'u'. To constrain the noise amplification of a MIMO response, select multiple signals

or a vector-valued signal.

• Specify stochastic outputs

Variance Goal